1. Field of the Invention
The present invention relates to an inoculating and cultivating method for the so-called "vessel" cultivation of Lentinus edodes, using a vessel such as a bottle or a bag, in which after 50 to 60 days' cultivation of hyphae, the culture medium is drawn out from the vessel, whereby it is possible to cause fruit bodies to grow from the entire surface (except the bottom face) of the culture medium.
Vessel cultivation, especially in bottles, has heretofore been widely practiced on an industrial scale for the cultivation of Flammulina velutipes, Pleurotus ostreatus, Pholiota nameko and the like. According to such vessel cultivation method, in general, as shown in FIGS. 1 and 2, 400 to 800 g of a culture medium 1 comprising a mixture of sawdust, rice bran, water and the like is placed in a heat-resistant synthetic resin bottle having a capacity of 500 to 100 ml, and one seed-inoculating and air-permeating hole 2 is formed at the center of the culture medium so that the hole extends substantially to the bottom of the bottle. An air filter such as a paper plug or a cotton plug is placed on the bottle mouth so as to prevent intrusion of miscellaneous unwanted fungi and bacteria. Then, the bottle is heated and sterilized, and after cooling, the desired fungus seed is inoculated on the entire top face of the culture medium and in the hole formed at the center thereof. Then, hyphae are sufficiently propagated in the culture medium at appropriate temperatures, the air filter on the bottle mouth is removed and fruit bodies are caused to grow from the bottle mouth under appropriate temperature and humidity conditions. The time required for accomplishing all of the foregoing steps is 50 to 60 days and the amount of harvested fruit bodies is generally 60 to 120 g per bottle. This method is excellent in the feature that (1) the culture medium is scarcely or not at all contaminated by miscellaneous unwanted fungi and bacteria and (2) because many of the steps can be performed mechanically, the cultivation process as a whole can easily be standardized. The bottles that are customarily used for this cultivation method include a blown bottle having a relatively small mouth diameter of about 5 to about 6 cm as shown in FIG. 1 and a wide-mouthed bottle or pot, like a flower pot, having a mouth diameter of about 10 to about 13 cm as shown in FIG. 2. The blown bottle is used for cultivation of Flammulina veutipes and Pleurotus ostreatus and the wide-mouthed bottle or pot is used for cultivation of Pholiota nameko and and Pleurotus ostreatus.
According to our previously proposed cultivation method disclosed in Japanese patent application No. 59815/76, filed May 24, 1976 (corresponding to U.S. Ser. No. 794,100, filed May 5, 1977), the entire contents of which are incorporated herein by reference, in which a coating material, which is air permeable and is not decomposed by hyphae of Lentinus edodes, is locally applied to the mushroom-growing surface of the culture medium, it became possible for the first time to cause fruit bodies of Lentinus edodes to grow from bottle mouths in from 50 to 60 days' cultivation time according to the foregoing procedures of the conventional bottle cultivation. The present invention provides an improved method for the vessel cultivation of Lentinus edodes in which the cultivation can be performed more efficiently. In the case of Flammulina veutipes and Pleurotus ostreatus, fruit bodies form a colony by branching, but in the case of Lentinus edodes, the respective fruit bodies tend to grow independently and generation of large quantities of fruit bodies from a small mushroom-growing surface area cannot be expected. Further, because fruit bodies of Lentinus edodes have a large cap, in order to prevent deformation caused by abutting of caps against one another and subsequent reduction of the commercial value of the mushroom produce, it is necessary to provide a relatively large mushroom-growing area and a sufficient space between adjacent fruit bodies.
For the foregoing reasons, there has been adopted a method for bottle cultivation of Lentinus edodes in which a wide-mouthed bottle or pot is used and the operations are carried out according to the above-described conventional bottle cultivation procedure and, after hyphae have sufficiently grown in the culture medium, the culture medium is taken out from the bottle, in the form of a unitary or one-piece structure, so that fruit bodies will grow from the entire surface of the culture medium inclusive of the side faces, but excluding the bottom face of the culture medium. However, according to this method, even though after a relatively short-period cultivation conducted for 50 to 60 days, hyphae grow sufficiently in the entire culture medium, fruit bodies are scarcely grown from the side faces of the culture medium, and the intended object of this invention cannot be attained.
In order to clarify the cause of this undesirable phenomenon, we made various investigations and experiments, and as a result, it was found that the above undesirable phenomenon probably is due to the following important inherent biological properties of Lentinus edodes:
1. In order for hyphae on the surface of the culture medium to form fruit bodies, they must reach a certain hypha age, and as the distance between the surface portion of the hypya and the inoculation position becomes greater, a longer time is required for the hypha to reach the above certain age. In other words, hyphae located at positions closer to the inoculation position reach a fruit body-forming age more rapidly. PA1 2. Fruit bodies can grow only from that area of the surface of the culture medium which has been sufficiently permeated by air from the start of the cultivation of hyphae (from a time before the initiation of the fruit body-growing treatment).